One purpose of the present invention is to provide a solution to the problem of either deliberate or inadvertent alteration of recordings. In this context, “recordings” refers to all recordings, including digital images, data files, and the more common audio recording.
Photographs, movies and printed materials have historically been regarded as media that can be trusted to be authentic copies of the original. Early attempts at alteration of photographs for the purposes of revisionist history were almost comically detectable with five people sitting at a table, but six pairs of legs underneath. Hand written, permanently bound, notebooks are used in research laboratories for their resistance against attempts at alteration. Recent technological advances have brought the ability to alter images to the neophyte level. When a master employs the advanced technology the alterations are almost completely undetectable. For this reason digital photography is seldom used in situations when “chain of custody” requirements exist to protect the authenticity of a recording be it photographic, written or auditory. For example, the picture of an accident scene could be altered to show bottles of alcoholic beverages around the driver, even if those bottles hadn't really been there when the picture was taken, but were a post accident embellishment.
A digital camera with apparatus for authentication of images produced from an image file is disclosed in U.S. Pat. No. 5,499,294. Referring to FIG. 3A of U.S. Pat. No. 5,499,294, a block diagram of a system including a digital camera is shown that produces a file image with a digital signature. A device specific decryption key is required to allow a file image to be authenticated. Furthermore, in order to determine whether a file image is authentic, the person performing the authentication must know which camera took the picture; due to the fact that each camera includes a unique private encryption key.
Another purpose of the present invention is to provide a system and apparatus for authenticating and searching data. Traditionally, the self-authentication of a data file and the indexing of a data file were technologically incompatible because self-authentication requires that the file is uncompromised, and indexing requires that the file is disassembled. The disassembly of a file is an unacceptable alteration of the file for verification of the file's integrity.
However, there is a continuing and ongoing need for a system and apparatus that creates self-authenticating copies of files received from an external system so that the integrity of the files can be verified upon their introduction into the system or apparatus. Simultaneously, there is a continuing and ongoing need to be able to search stored files.